After SLIB is installed, the following Scheme expression must be
executed before the SLIB facilities can be used:

(use-modules (ice-9 slib))

require can then be used in the usual way (see Require in The SLIB Manual). For example,

(use-modules (ice-9 slib))
(require 'primes)
(prime? 13)
⇒ #t

A few Guile core functions are overridden by the SLIB setups; for
example the SLIB version of delete-file returns a boolean
indicating success or failure, whereas the Guile core version throws
an error for failure. In general (and as might be expected) when SLIB
is loaded it’s the SLIB specifications that are followed.